AU2019277321B2

AU2019277321B2 - Dental fluoro-aluminosilicate glass powder

Info

Publication number: AU2019277321B2
Application number: AU2019277321A
Authority: AU
Inventors: Ayaka FUJIMOTO; Naofumi Matsumoto; Mizuki Nakayama; Yusuke Shimada; Ryosuke YOSHIMITSU
Original assignee: GC Corp; GC Dental Industiral Corp
Current assignee: GC Corp
Priority date: 2018-05-30
Filing date: 2019-05-08
Publication date: 2022-02-10
Anticipated expiration: 2039-05-08
Also published as: CN112118822B; KR102478008B1; PH12020552007A1; CA3101605C; US11337898B2; EP3804687A1; KR20210003887A; AU2019277321A1; JP7061189B2; US20210196580A1; CA3101605A1; ZA202007318B; WO2019230309A1; BR112020022768A2; MY193733A; JPWO2019230309A1; CN112118822A; SG11202011516TA; EP3804687A4

Abstract

This dental fluoro-aluminosilicate glass powder according to one embodiment of the present invention has a volume-based 50%-diameter of 5.0-9.0 μm and a volume-based 10%-diameter of at least 2.4 μm.

Description

DESCRIPTION DENTAL FLUOROALUMINOSILICATE GLASS POWDER FIELD OF THE INVENTION

[0001]

The present invention relates to a dental

fluoroaluminosilicate glass powder and a glass ionomer

cement.

BACKGROUND OF THE INVENTION

[0002] A glass ionomer cement has excellent characteristics,

for example, extremely favorable biocompatibility,

excellent aesthetic property of semi-transparent cured

product, excellent adhesion to tooth substrates such as

enamel and dentine, and anticariogenic effect by the

fluoride. Thus, the glass ionomer cement is widely used in

dentistry, for example for filling cavities of dental

caries, for luting crowns, inlays, bridges and orthotic

bands, for cavity linings, sealers for filling root canals,

core build up, fissure sealant, and the like.

[0003] A glass ionomer cement generally has an aqueous

solution of polycarboxylic acid-based polymer and

fluoroaluminosilicate glass powder (for example, refer to

Patent Document 1).

[0004]

Here, when an aqueous solution of polycarboxylic

acid-based polymer and a fluoroaluminosilicate glass powder

are mixed, an aluminum ion (Al 3+) released from the

fluoroaluminosilicate glass powder and the conjugate base

of the polycarboxylic acid-based polymer are ionically crosslinked and cured by the acid-base reaction of the fluoroaluminosilicate glass powder and the polycarboxylic acid-based polymer.

RELATED-ART DOCUMENT

Patent Documents

[0005] Patent Document 1: International Publication No.

WO2016/002600

SUMMARY OF THE INVENTION

Problems to be Solved by the Invention

[0006] Generally, the compressive strength of the cured

product of glass ionomer cement is desired to be improved.

For this purpose, a fluoroaluminosilicate glass powder

having a small particle size is considered to be used.

[0007]

However, when a fluoroaluminosilicate glass powder

having a small particle size is used, the problem arises

that the time from the start of mixing a

fluoroaluminosilicate glass powder with an aqueous solution

of polycarboxylic acid-based polymer to the curing thereof,

that is, the working time of the glass ionomer cement,

becomes shorter.

[0008] An aspect of the present invention has the object of

providing a dental fluoroaluminosilicate glass powder

capable of extending the working time of the glass ionomer

cement and of increasing the compressive strength of the

cured product of the glass ionomer cement.

Means for Solving the Problems

[0009] One aspect of the present invention relates to a dental fluoroaluminosilicate glass powder, a 50th percentile volume diameter of which is 5.0 p4m or more and 9.0 p4m or less, and a th percentile volume diameter of which is 2.4 4m or more. In a related aspect of the present invention, there is provided a dental fluoroaluminosilicate glass powder, a 50th percentile volume diameter of which is 5.0 p4m or more and 9.0 p4m or less, a 10th percentile volume diameter of which is 2.4 p4m or more, and a 90th percentile volume diameter of which is 16.2 p4m or more and 20.0 4m or less.

Effects of the Invention

[0010] In one aspect of the present invention, a dental fluoroaluminosilicate glass powder can be provided that is capable of extending the working time of the glass ionomer cement and of increasing the compressive strength of the cured product of the glass ionomer cement.

DETAILED DESCRIPTION

[0011] In the following, embodiments for carrying out the present invention will be described.

[0012] <Dental Fluoroaluminosilicate Glass Powder> 1. The 50th percentile volume diameter(d50) of the dental fluoroaluminosilicate glass powder of the present embodiment is 5.0 p4m or more and 9.0 p4m or less, and is preferably 5.1 p4m or more and 8.0 p4m or less. When the d50 of the dental fluoroaluminosilicate glass powder is less than 5.0 p4m, the working time of the glass ionomer cement becomes shorter. On the other hand, when the d50 of the dental fluoroaluminosilicate glass powder exceeds 9.0 p4m, the compressive strength of the cured product of the glass ionomer cement is decreased.

[0013]

The 10th percentile volume diameter(d10) of the

dental fluoroaluminosilicate glass powder of the present

embodiment is 2.4 pm or more, and is preferably 2.7 pm or

more. When the d10 of the dental fluoroaluminosilicate

glass powder is less than 2.4 p4m, the aqueous solution of

the polycarboxylic acid-based polymer and the dental

fluoroaluminosilicate glass powder cannot be mixed.

[0014]

The d10 of the dental fluoroaluminosilicate glass

powder of the present embodiment is usually 4.8 pm or less.

[0015]

The 90th percentile volume diameter(d90) of the

dental fluoroaluminosilicate glass powder of the present

embodiment is 13.0 pm or more and 20.0 pm or less, and is

preferably 14.0 pm or more and 19.0 pm or less. When the

d90 of the dental fluoroaluminosilicate glass powder of the

present embodiment is 13.0 pm or more, the working time of

the glass ionomer cement is extended. When the d90 of the

dental fluoroaluminosilicate glass powder of the present

embodiment is 20 pm or less, the compressive strength of

the cured product of the glass ionomer cement is increased.

[0016]

The content of fluorine (F) in the dental

fluoroaluminosilicate glass powder of the present

embodiment is preferably 1 to 30% by mass and more

preferably 3 to 20% by mass.

[0017]

The content of aluminum in the dental

fluoroaluminosilicate glass powder of the present

embodiment is preferably 15 to 35% by mass and more

preferably 20 to 30% by mass in terms of the amount

converted to aluminum oxide (A1 2 0 3 )

[0018]

The content of silicon in the dental

fluoroaluminosilicate glass powder of the present

embodiment is preferably 15 to 50% by mass and more

preferably 20 to 40% by mass in terms of the amount

converted to silicon oxide (SiO 2 ).

[0019]

The content of phosphorus in the dental

fluoroaluminosilicate glass powder of the present

embodiment is preferably 0 to 10% by mass and more

preferably 1 to 5% by mass in terms of the amount converted

to phosphorus (V) oxide (P 2 0 5 ) .

[0020] The content of sodium in the dental

fluoroaluminosilicate glass powder of the present

embodiment is preferably 0 to 15% by mass and more

preferably 1 to 10% by mass in terms of the amount

converted to sodium oxide (Na20).

[0021]

The content of potassium in the dental

fluoroaluminosilicate glass powder of the present

embodiment is preferably 0 to 10% by mass and more

preferably 1 to 5% by mass in terms of the amount converted

to potassium oxide (K 2 0)

[0022] The content of strontium in the dental

fluoroaluminosilicate glass powder of the present

embodiment is preferably 0 to 40% by mass and more

preferably 10 to 30% by mass in terms of the amount

converted to strontium oxide (SrO).

[0023] The content of lanthanum in the dental

fluoroaluminosilicate glass powder of the present

embodiment is preferably 0 to 50% by mass and more preferably 1 to 40% by mass in terms of the amount converted to lanthanum oxide (La203)

[0024]

The dental fluoroaluminosilicate glass powder of the

present embodiment can be applied to, for example, a glass

ionomer cement or the like.

[0025] <Glass Tonomer Cement>

The glass ionomer cement of the present embodiment

contains the dental fluoroaluminosilicate glass powder of

the present embodiment and an aqueous solution of a

polycarboxylic acid-based polymer.

[0026] The polycarboxylic acid-based polymer is not

particularly limited, but for example, a homopolymer or

copolymer of a,p-unsaturated carboxylic acid can be used.

[0027]

Examples of the a,p-unsaturated carboxylic acid

include acrylic acid, methacrylic acid, 2-chloroacrylic

acid, 3-chloroacrylic acid, aconitic acid, mesaconic acid,

maleic acid, itaconic acid, fumaric acid, glutaconic acid,

citraconic acid, and the like.

[0028] In addition, the polycarboxylic acid-based polymer

may be a copolymer of an a,p-unsaturated carboxylic acid

and a monomer capable of copolymerizing with the a,

unsaturated carboxylic acid.

[0029] Examples of the component that can be copolymerized

with the a,p-unsaturated carboxylic acid include

acrylamide, acrylonitrile, methacrylic acid ester,

acrylates, vinyl chloride, allyl chloride, vinyl acetate,

and the like.

[0030] In this case, the ratio of the a,p-unsaturated

carboxylic acid to the monomer constituting the

polycarboxylic acid-based polymer is preferably 50% by mass

or more.

[0031]

The polycarboxylic acid-based polymer is preferably a

homopolymer or copolymer of acrylic acid or itaconic acid.

[0032] Note that at least a part of the polycarboxylic acid

based polymer may be powder.

[0033] In the glass ionomer cement of the present

embodiment, when the dental fluoroaluminosilicate glass

powder and the aqueous solution of the polycarboxylic acid

based polymer are mixed, the mass ratio of the dental

fluoroaluminosilicate glass powder with respect to the

aqueous solution of the polycarboxylic acid-based polymer

(hereinafter referred to as powder-liquid ratio) is

preferably 1 to 5 and more preferably 2.8 to 4.0. When the

powder-liquid ratio is 1 or more, the compressive strength

of the cured product of the glass ionomer cement is further

increased. When the powder-liquid ratio is 5 or less, the

dental fluoroaluminosilicate glass powder and the aqueous

solution of the polycarboxylic acid-based polymer are

easily mixed.

EXAMPLES

[0034]

Examples of the present invention will be described

below, but the present invention is not limited to the

examples.

[0035]

28 g of silica (SiO 2 ), 10 g of alumina (A1 2 0 3 ), 18 g of aluminum fluoride (AlF 3 ), 17 g of strontium fluoride

(SrF2), 11 g of aluminum phosphate (AlPO 4 ), 6 g of cryolite

(Na 3AlF 6 ), 6 g of potassium fluoride (KF) and 3 g of

lanthanum oxide (La203) were sufficiently mixed using a

mortar. The obtained mixture was put into a magnetic

crucible and left standing in an electric furnace. The

temperature of the electric furnace was raised to 1300°C,

the mixture was melted and homogenized sufficiently, and

then poured into water to obtain a bulk

fluoroaluminosilicate glass. The obtained bulk

fluoroaluminosilicate glass was crushed with a ball mill

for 20 hours and then passed through a 120-mesh sieve to

obtain fluoroaluminosilicate glass powder.

[0036] It was confirmed that the obtained

fluoroaluminosilicate glass powder contained the following

composition by the fluorescent X-ray analysis.

[0037] F: 18% by mass

Na20: 3% by mass

A1 2 0 3 : 22% by mass

SiO 2 : 22% by mass P 205 : 5% by mass

K 20: 5% by mass

SrO: 21% by mass

La203: 4% by mass

The obtained fluoroaluminosilicate glass powder was

further pulverized using a ball mill to adjust the particle

size distribution, to obtain fluoroaluminosilicate glass

powders of Examples 1 to 6 and Comparative Examples 1 to 3.

[0038]

<Particle Size Distribution of Fluoroaluminosilicate Glass

Powder>

The particle size distribution of the

fluoroaluminosilicate glass powder was measured using a

laser diffraction/scattering particle size distribution

measuring device LA-950 (manufactured by HORIBA Ltd.).

Specifically, first, fluoroaluminosilicate glass powder was

dispersed in a 0.1% by mass of hexametaphosphoric acid

aqueous solution to obtain a suspension. Next, a small

amount (0.5 ml) of the suspension was added to circulated

0.1% by mass of hexametaphosphoric acid aqueous solution,

and the particle size distribution of the

fluoroaluminosilicate glass powder was measured.

[0039] <Working time of Glass Tonomer Cement>

The fluoroaluminosilicate glass powder and a 50% by

mass of polyacrylic acid aqueous solution were mixed at a

predetermined powder-liquid ratio (see Table 1). Next, the

mixed product was pulled up with a spatula, with the

spatula being in contact with the mixed product of glass

ionomer cement, and the operation of confirming whether the

mixed product of glass ionomer cement adheres to the

spatula was repeated. Thereby, the time at which the mixed

product of the glass ionomer cement no longer adhered to

the spatula after the start of mixing of the

fluoroaluminosilicate glass powder and the 50% by mass of

polyacrylic acid-based aqueous solution was measured. The

time measured was considered as the working time of the

glass ionomer cement.

[0040] The criteria for determining the working time of the

glass ionomer cement was as follows.

[0041]

Excellent: the working time of the glass ionomer

cement was 1 minute 30 seconds or more.

Good: the working time of the glass ionomer cement

was 1 minute 15 seconds or more and less than 1 minute 30

seconds.

Not good: the working time of the glass ionomer

cement was less than 1 minute 15 seconds.

<Compressive Strength of Cured Product of Glass Ionomer

Cement>

The fluoroaluminosilicate glass powder and a 50% by

mass of polyacrylic acid aqueous solution were mixed at a

predetermined powder-liquid ratio (see Table 1) to obtain a

mixed product of glass ionomer cement. Next, 4.2 g of a

mixed product of glass ionomer cement was filled in a mold

having a height of 6 mm and a diameter of 4 mm, and was

pressure-contacted and then allowed to stand in a

thermostatic chamber at 37°C and 100% RH for 1 hour. After

the mold was taken out from the thermostatic chamber, the

cured product of the glass ionomer cement was removed from

the mold and immersed in water at 37°C for 24 hours. Next,

the water of the cured product of the glass ionomer cement

was wiped off. Then, a load was applied in the

longitudinal direction of the cured product of the glass

ionomer cement using the precision universal testing

machine (autograph) (manufactured by Shimadzu Corp.), and

the load when the cured product of the glass ionomer cement

was broken was measured (hereinafter, referred to as the

maximum load).

[0042] Next, the compressive strength C [MPa] of the cured

product of the glass ionomer cement was calculated by the

formula:

C = 4p/ (rd2

) Here, p is the maximum load [N], and d is the diameter [mm]

of the cured product of the glass ionomer cement.

[0043]

The criteria for determining the compressive strength

of the cured product of the glass ionomer cement was as

follows.

[0044]

Good: the compressive strength of the cured product

of the glass ionomer cement was 200 MPa or more.

Not good: the compressive strength of the cured

product of the glass ionomer cement was less than 200 MPa.

Table 1 shows the working time of the glass ionomer

cement and the evaluation results of the compressive

strength of the cured product of the glass ionomer cement.

[0045]

[Table 1]

Examples Comparative Examples 1 2 3 4 5 6 1 2 3 di [y m] 3.0 2.7 3.2 2.8 2.4 3.2 4.7 2.0 1.3 d50 [ m] 6.3 5.1 6.9 5.8 6.3 6.9 10.1 5.0 2.1 d90 [ m] 16.2 14.0 18.1 16.8 13.2 18.1 18.5 9.1 3.6 Powder-liquid ratio 3.2 3.2 3.2 3.2 3.2 3.4 3.2 3.2 3.2

1'30" 1'30" 1'40" 1'40" 1'15' '15' 1'50" - Working time Excellent Excellent Excellent Excellent Good Good Excellent -

Compressive 262 241 220 235 210 249 182 - strengthE[MPa] Good Good Good Good Good Good Notgood -

From Table 1, when the fluoroaluminosilicate glass

powders of Examples 1 to 6 were used, the working time of

the glass ionomer cement was extended, and the compression

strength of the hardened glass ionomer cement was

increased.

[0046]

On the other hand, the d50 of the

fluoroaluminosilicate glass powder in Comparative Example 1

was 10.1 pm. As a result, the compressive strength of the

cured product of the glass ionomer cement was decreased.

[0047]

Further, the d10 of the fluoroaluminosilicate glass

powder in Comparative Examples 2 and 3 were 2.0 pm and 1.3

pm, respectively. As a result, the fluoroaluminosilicate

glass powder in Comparative Examples 2 and 3 were not able

to be mixed with 50% by mass of polyacrylic acid aqueous

solution.

[0048]

This international application is based on and claims

priority of Japanese Patent Application No. 2018-103396

filed May 30, 2018, the entire contents of which are hereby

incorporated by reference.

Claims

1. A dental fluoroaluminosilicate glass powder, a 50th percentile volume diameter of which is 5.0 pm or more and 9.0 pm or less, a 10th percentile volume diameter of which is 2.4 pm or more, and a 90th percentile volume diameter of which is 16.2 pm or more and 20.0 pm or less.

2. The dental fluoroaluminosilicate glass powder according to claim 1, wherein the powder is for a glass ionomer cement.

3. The dental fluoroaluminosilicate glass powder according to claim 1 or claim 2, wherein the powder comprises: 1 to 30% by mass of fluorine; 0 to 15% by mass of sodium oxide; 15 to 35% by mass of aluminium oxide; 15 to 50% by mass of silicon oxide; 0 to 10% by mass of phosphorous(V) oxide; 0 to 10% by mass of potassium oxide; 0 to 40% by mass of strontium oxide; and 0 to 50% by mass of lanthanum oxide.

4. The dental fluoroaluminosilicate glass powder according to any one of claims 1 to 3, wherein the 10th percentile volume diameter of which is 3.2 pm or more and 4.8 pm or less.

5. A glass ionomer cement comprising: the dental fluoroaluminosilicate glass powder of claim 1; and an aqueous solution of a polycarboxylic acid-based polymer.

6. The glass ionomer cement according to claim 5, wherein the mass ratio of the dental fluoroaluminosilicate glass powder with respect to the aqueous solution of the polycarboxylic acid-based polymer is 2.8 to 4.0.

7. The glass ionomer cement according to claim 5 or claim 6, wherein a working time of the glass ionomer cement is 1 minute seconds or more.

8. The glass ionomer cement according to any one of claims 5 to 7, wherein a compressive strength of a cured product of the glass ionomer cement is 200 MPa or more.

GC Corporation Patent Attorneys for the Applicant/Nominated Person SPRUSON & FERGUSON